function create_track_selector_buttons(contest) {
  var str = "";
  $.each(contest.tracks, function(index, value) {
    console.log("index: " + index + " > " + value.name)
    str += "<button onclick='select_track(" + index + ")' class='btn " + (index % 2 == 0 ? "btn-primary" : "btn-success") + "'>选择 " + value.name + "</button><br />";
  });

  return str;
}
